Asparagus is generally grown in sandy soil, so you'll need to rinse it thoroughly with cold water. Break off the woody base of asparagus spear, you can also cut it but breaking works just fine - it should snap right off when you find the right spot.
I prefer to remove the bumps or scales on the spears with a small knife or vegetable peeler, this is not 100% necessary, but gives the asparagus spears a clean and smooth appearance.
Cooking methods
Shock Blanching
This method requires boiling asparagus for less than 5 minutes, then quickly dumping it into an ice
bath , shocking the asparagus to stop cooking. The end result is a well cooked, but cold asparagus.
You can re-heat it to serve later. The best way is by warming it in a shallow baking dish. Cover
with boiling salted water then drain. Let it stand for about 10 minutes and serve warm.
Steaming
Steaming asparagus is probably the most common method for cooking it, other than boiling , which
destroys some of the flavor and nutritional value.
Naturally, a steamer works best, but a colander, or strainer will also suffice if a steamer is not
available.
Place your steamer basket or colander [assuming it fits properly] in a saucepan. Add enough water
so that it comes to the basket bottom, but doesn't come in contact with the basket or asparagus once
it is added.
Boil the water . Add asparagus to the steamer basket. Cover and reduce the heat, so that a steady
slow rolling boil is attained. Steam for up to 5 minutes, but no longer. The spears should still be
slightly crisp, but also tender. Simmer and Serve.
Roasting
Preheat the oven to 400 degrees F. Put your asparagus spears on a baking sheet or dish, and sprinkle moderately with olive oil. Brush the oil about , if need be to fully coat he spears. I like to
season with salt, black pepper and a pinch of garlic. Roast, uncovered, for 10 - 15 minutes, until
the asparagus is crispy and still tender. Turn the spears at least twice while roasting.
Grilling
Smother the asparagus in olive oil or melted butter. This will not only add flavor, but also prevent
the spears from burning onto the grill . Place your asparagus on a grill rack, or on a piece of
heavy duty aluminum foil, situated so the spears criss cross the grill wires and don't sink into
them . Preheat your gas grill then reduce the heat to medium. The asparagus should be ready in under
10 minutes.
If using a charcoal grill, it's best place the asparagus on a grill rack directly over the coals.
Grill it for up to 10 minutes turning as necessary.
Microwave
Place your asparagus spears in a microwave-safe dish, add 3 tablespoons of water per pound of
asparagus, and cover the bowl. Microwave, covered, on high until crisp but still tender. Generally 2
to 4 minutes.
http://luv2garden.com/asparagus_cooking.html